Blast chiller expressly for domestic use

ABSTRACT

Built-in domestic blast chiller expressly designed for domestic use. The hot components (compressor  6 , condenser  7 ) of the blast chiller are positioned on the upper part of its rear wall ( 24 ) and in a seat ( 4 ) so as to facilitate their ventilation and in order to leave room for an inner space ( 33 ) for accomodating baking sheets, trays or grills of the same dimensions as those of traditional domestic built-in ovens.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a blast chiller expressly designed fordomestic use. In fact, the blast chiller has been devised so as to workeffectively in typical domestic structures where peculiar requirementsare needed with respect to the industrial sector.

PRIOR ART TECHNIQUE

Blast chillers are fast cooling devices capable of rapidly reducing(about 90 minutes) the temperature of hot foods from the cookingtemperature to 3° C. (blast chilling), and to the temperature of −18° C.to the core in the case of freezing thus preserving the food in therefrigerator or in the freezer. Such treatment maintains the foodnutritional values while reducing bacteria proliferation. In fact, it isknown that quick freezing causes the formation of micro-crystals of thewater contained in foods, while slow freezing causes the formation ofmacro-crystals that, on the contrary, damage the molecular structure ofvitamins and proteins of the same foods. Furthermore, it is obvious thatthe more quickly foods are frozen the more easily bacteria proliferationis prevented.

This technology is especially used in professional kitchens ofrestaurants and in other commercial activities such as ice-cream shops,confectionary shops, etc. Therefore blast chillers are mainly of anindustrial or professional type.

The so called professional blast chillers are characterized by a ratherbulky structure, similar to a cupboard provided with a lower portion foraccommodating the “hot” functional components of a heat pump systemtopped by a compartment divided into a plurality of shelves whereon thefoods to be treated are placed. It is known that such “hot” componentscomprise a compressor for a cooling fluid connected to a condenser. Afan is mounted in the proximity of the condenser so as to cool the samecondenser. An evaporator is then mounted inside the food compartment.

It is also known that in such system the cooling fluid is compressedinside the compressor where it is overheated. Then the hot fluid goesinto the condenser where it exchanges heat with the ambient air, alsothanks to the fan that forces the ambient air to hit the condenser. Bygiving off heat the cooling fluid cools down. Subsequently, it goesthrough an expansion device, such as a capillary, exiting which itundergoes a quick volume expansion that causes its further cooling. Thecold fluid reaches the evaporator where it exchanges heat with the aircontained inside the above said food compartment. A further fan forcesthe air of the compartment to hit the evaporator so as the cooling downis quickened. Finally, the fluid which has absorbed the heat of the airin the compartment goes back to the compressor to start a new cycle.

In order to achieve the above said performances concerning the coolingtemperature in an acceptable times, it is necessary to use compressorshaving great powers which might reach even 5-8 kW. As a consequence, thedimensions of the same as well as those of the corresponding componentsof the cooling circuit are rather bulky. However, as it regardsprofessional use, the area where such machines are accommodated does notrequire particular solutions from the design point of view.

Given the above said importance from the organoleptic and health pointof view of a rapid lowering of the temperature, also domestic blastchillers are becoming widely used.

Domestic blast chillers, differently from those for industrial use, havedefinitely more limiting requirements as far as space is concerned. Infact, kitchen furniture is standardized, especially for built-inhousehold appliances more and more frequently used for design reasons aswell.

At the same time, the performances, that is the cooling capacity in asatisfactory time, must be compared with the professional ones so as tojustify a domestic use. Therefore, in the standard spaces of built-inhousehold appliances, there must be both the above said functionalcompartment and the food compartment.

In order to meet these requirements, domestic built-in blast chillers ofthe prior art comprise a furniture unit having the same size as aconventional built-in oven. The furniture unit is divided into twocompartments, a left one and a right one, wherein one of the two hasusually a size greater than the other one. The smaller compartment isused to accommodate the “hot” compartment of the heat pump system, whilethe bigger compartment is used for the foods to be treated.

It is obvious that the above said construction forces to reduce thesizes of the grills, trays or baking sheets for the foods. In otherwords, it is not possible to use baking sheets of the size the same asthose for ovens, but usually standard sized gastronorm baking sheets(standard EN 631) are used in blast chillers which are absolutelyunsuitable for built-in ovens.

It results that producers, who are usually those who make traditionalhousehold appliances such as built-in ovens, have to invest specificresources to make trays, baking sheets or grills only for thosehousehold appliances, resulting in an evident increase of productioncosts.

For example, in EP1098149 there is disclosed a domestic built-in blastchiller comprising a furniture unit of basically the same size as thatof a traditional built-in oven. The air circulation includes a frontintake provided in the furniture unit lower edge and a front dischargeprovided in the upper edge of the same furniture unit, hence guiding theair to a path having two successive deviations, each one at 90° degrees.

The hot component is accommodated in a compartment which takes the wholeheight of the left rear corner, thus reducing the room available for thefoods to be treated for the whole height of the functional compartment,as a consequence it is necessary to use custom-made grills, trays andbaking sheets and that have a pentagonal perimeter, with a clearincrease of production costs.

In this blast chiller the air flux sucked horizontally reaches the rearwall where it deviates by 90 degrees upwards, entering the above saidcompartment at the left rear corner. Then it moves up vertically,passing through the fan and then around the compressor and thecondenser. When the air reaches the top part of the left compartment, itmust deviate by another 90 degrees so as to reach horizontally the upperedge and exit from the front wall.

Alternatively to the above said lateral positioning of the “hot”component, the prior art envisages the condenser in the upper part or inthe lower part and at the rear with respect to the food treatmentcompartment or box and the compressor always in the lower part and atthe rear, while the “cold” component (evaporator) is usually positionedin the upper part and at a level higher than the condenser. In thisconfiguration, the condenser, as it is lower than the evaporator,reduces, in the upper part, the depth of the refrigerating box, whilethe compressor reduces it in the lower part, resulting in the fact thatthe entire depth of the compartment is diminished. Therefore, thecompartment can accommodate trays and the like having standardgastronorm sizes or smaller sizes.

It is also to note that anyway the construction is relatively complexwith clear high production costs.

SUMMARY OF THE INVENTION

Object of the present invention is therefore that of providing a blastchiller expressly for domestic use capable of accommodating thereincompletely traditional trays, baking sheets or grills, or in otherwords, supports for foods of the same size as those used for built-inovens, but, at the same time, it must ensure high performances and besimple and cost effective to make.

In order to reach such object, it is obviously impossible to keep thelateral positioning of the compressor, condenser and related fan. It isneither possible to place them in the upper or in the lower part and atthe rear of the compartment for the just described reasons.

Therefore, it has been devised a different arrangement of the “hot”component, that is of the compressor and of the condenser, which wouldsolve all the above said drawbacks and would ensure a structuralsimplicity and cost effectiveness.

A first object of the present invention is then a built-in domesticblast chiller comprising a blast chilling system with a refrigerationcycle, wherein the “hot” component, that is compressor, condenser andrelated fan, is accommodated in a specific seat outside therefrigerating box.

A second object of the invention is a blast chiller simple and costeffective to make.

A third object is a blast chiller which makes it possible to accommodatetherein baking sheets, trays or grills of the same size as those for atraditional built-in oven for domestic use.

A fourth object is a blast chiller provided with the best performance ofits refrigeration system.

A further object is a method for cooling the “hot” component of therefrigeration cycle of a built-in domestic blast chiller in a simple andadvantageous way.

BRIEF DESCRIPTION OF FIGURES

Further characteristics and advantages of the domestic blast chillerwill become more apparent from the following description of anembodiment for exemplification only but not limited to with reference tothe following figures, wherein:

FIG. 1 is a schematic side sectional view of a kitchen furniture unitwith a blast chiller accommodated therein, this too in a sectional view,according to the present invention;

FIG. 2 shows a rear axonometric view of the blast chiller of theinvention;

FIG. 3 shows a front schematic axonometric view of the blast chiller ofFIG. 2 having the food treatment compartment door open.

DETAILED DESCRIPTION OF THE INVENTION

The idea upon which the present invention is based is that ofpositioning in the upper part both the “hot” components, that iscompressor and condenser of the refrigeration system. But it hasexperimentally been observed that the above said positioning causes agreat number of problems mainly connected with the cooling air-flux.

In particular, after studying fluxes accurately, it has been understoodhow the generated air-flux interacts on the “hot” ventilated parts,condenser and compressor, when the cooling ducts are positioned at therear in a built-in furniture unit. The study has begun by observing themotion of the incoming cooling air-fluxes in the front portion of ablast chiller of the prior art and its behaviour both upstream anddownstream of the condenser.

It must also be taken into consideration that at the front, at the upperpart and at the lower part, depending on the condenser position, theblast chiller has an aperture, usually finned, so as to allow theincoming of the air sucked from the outside by the fans mounted in theproximity of the condenser in order to cool the condenser itself. Thisair, after having cooled the condenser is blown into the rear part ofthe seat of the blast chiller in the furniture unit where it isbuilt-in. In this area, there is a space in the furniture unit thatallows the exit of the hot air which obviously must not be stagnant inthe furniture unit itself.

In fact, the surface of the thermal exchange of the condenser isparallel to the direction of the incoming air which is suckedorthogonally with respect to the front wall of the blast chiller. Thisoccurs because the suction fan is positioned below the condenser,therefore it, too, horizontally, that is having the rotating axisorthogonal to the surface whereon it blows the cooling air.

In this position, the sucked air must necessarily undergo a deviation by90° in correspondence of the fan. Through experimentation measurements,it has surprisingly been observed that such deviation implies a ratherrelevant loss of flux, that is of pressure, probably due to theformation of turbulent flows caused by the same deviation.

The above mentioned measurements of the flux of the cooling air havebrought to think that the pressure loss might affect the systemefficiency. In fact, it can be hypothesized that a flux which is notoptimal does not ensure an efficient cooling of the condenser, resultingin a non-optimal performance of the whole system (COP).

Now, it has been devised to try to create a flux of the cooling airwhich would be the most ordered possible, that is the most rectilinearpossible for the whole path of the cooling air both downstream andupstream of the condenser and, of course, also in correspondence of thecondenser itself.

With reference to FIG. 1, there is shown a lateral section of a piece offurniture F provided with a compartment S1 for accommodating a built-inhousehold appliance such a traditional oven or a blast chiller forcooked foods of standard dimensions. As it can be seen, the piece offurniture can comprise, as usual, more compartments S2, S3, so as toform a column-like furniture unit F to accommodate more householdappliances, kitchenware or foodstuffs depending on the necessities orpreferences of usage of the furniture unit itself. Anyway, the furnitureunit F is provided with a front opening O1 positioned in the lower partin the proximity of the floor (not shown), usually with a completelytraditional grille (not shown), especially when the furniture unit isused for built-in fridges. At the rear of the opening, the furnitureunit F defines a horizontal passage P for the ventilation air in-flux.In the proximity of the rear wall W of the furniture unit F, saidpassage P has an upper window O2 which allows the air to be liftedupwards, as shown by the arrows, passing into the above compartment S2.In turn, the compartment S2 has its own window O3 on the upper wall,aligned with the window O2 of the above said passage P, which directlycommunicates with the compartment S1. Similarly, another window O4 isprovided between the compartment S1 and the above compartment S3,aligned as well with the respective windows O2 and O3. Finally, theventilation air exits the compartment S3, and hence the furniture unitF, too, through an exit window O5 positioned in the upper wall of thefurniture unit F.

In the compartment S1 there is accommodated a blast chiller 1 for freshor cooked foods. As better shown in FIGS. 2 and 3, this blast chiller 1is a generally box-like parallelepiped having a container 2 toreversibly close a food treatment box 3 (FIG. 3).

It is to note that in the description of the invention hereinafter termsreferring to the position of any element or component of the blastchiller or of the built-in furniture unit such as upper, lower, above,below, right, left, vertical, horizontal and the like are to beunderstood as referring to the objects in their normal condition of useand of assembly. Therefore, also when the blast chiller is not mounted,the skilled in the art is anyhow capable of recognizing the above saidreferences.

The container 2 comprises a front door 20 horizontally hinged so as toflap open or, according to a second configuration (not shown), the doorcan also be hinged vertically so as to open laterally. Above the door 20it is provided with a series of commands C with related display to setthe functions of the blast chiller 1. Furthermore, the container 2 iscompleted by two side walls 21, an upper wall 22, a lower wall 23, and arear wall 24. The side 21, the upper 22 and the lower 23 walls arebasically flat.

Advantageously, the rear wall 24 is shaped so as to form a seat 4 toaccommodate the “hot” component of the heat pump refrigeration system ofthe blast chiller 1. Preferably, with reference to FIG. 1, the rear wall24 is a portion of a casing containing the box 3 separated from thecontainer 2. In particular, this rear wall 24 comprises a first portion241 generally inclined downward and rearward, that is away from the door20, and a second portion 242 substantially vertical, that is orthogonalto the lower wall 23. The casing of the box 3 is then completed by twoside walls (not shown), a lower wall 31 and an upper wall 32 which joinsup with said rear wall 24, as shown in FIG. 1. Practically, the rearwall 24 would constitute the rear wall of both the container 2 and thebox 3. Alternatively, the side 21, upper 22, lower 23 and rear 24 wallscan belong to a single casing, that is the container 2, whose insideconstitutes the refrigeration box.

The seat 4, thus defined, comprises a support 5 preferably shelf-like,to support a compressor 6, a condenser 7 and cooling means 8 for thecompressor and the condenser.

In particular, the support 5 is provided with apertures to allow thepassage of the cooling air without any obstacles which might block itsflux. On this support 5 there are fixed said cooling means 8 comprisingat least a fan adapted for suction of the air from the furniture unitbottom and for forcedly pushing it directly on the condenser 7. In fact,the condenser 7 is mounted just above the fan 8 in order to be totallyhit by the air just blown by the fan itself. Laterally to the fan8/condenser 7 assembly there is the compressor 6 so that, at least inpart, it, too, can be brushed by the cooling air.

It is to keep in mind that the second portion 242 of the rear wall 24thus defines a suction guide having a smaller section which is before anexpansion section in correspondence of the first portion 241. Thesection of the passage of the air, in correspondence of the firstportion 241, is therefore larger than the section of the passage of theair obtained in correspondence of the second portion 242.

In other words, the section of the passage of the air is thus smallerupstream of the fan 8 and expanded in correspondence and downstream ofthe fan 8 itself. The passage of the air is therefore basically directedvertically and hits only the rear wall 24, thus obtaining the furtheradvantage of making the thermal exchange more efficient. In fact, in theblast chiller according to the invention the upper wall 22 is not hit bythe flux of the hot air as, on the contrary, it happens in the blastchillers of the prior art such as EP1098149.

Furthermore, advantageously the just described rear wall 24, and asbetter identified in the section of FIG. 1, cooperates with the rearwall W of the furniture unit in order to form a channel for guiding thecooling air of the “hot” component. Therefore, such geometry not onlyforms the seat 4 for accommodating the “hot” component but it also formsthe ventilation channel of the cooling air of this same component.

In particular, as shown by the direction of the arrows of FIG. 1, theair sucked by means of the above said fan 8 from the outside through theopening O1 on the bottom of the furniture unit F, reaches the window O2,after crossing it, the air flux follows a rectilinear path just in thevicinity of the rear wall W of the furniture unit inside the compartmentS2, below the accommodating compartment S1 of the blast chiller 1. Suchordered flux reaches the window O3 for entering the compartment S1basically below the “hot” component, substantially axially aligned withthe cooling fan 8 positioned just below the condenser 7. Here, the airis forced against the condenser 7 so as to hit it completely with asteady flux and without relevant pressure losses. After having passedthrough the condenser 7 the heated air moves up towards thecommunicating opening O4 between the compartment S1 and the compartmentS3 above and then moves on with a rectilinear motion toward the openingO5 for exiting the furniture unit F.

From the foregoing, it is clear that the flux of the cooling air entersthe lower part of the accommodating compartment S1 of the blast chiller1 in the vicinity of the wall W of the furniture unit F, following arectilinear and ordered motion. It is also to note that the flux when itenters the compartment S1 goes through a first channel having a smallersection defined, as previously described, by the rear wall W of thefurniture unit F and by the second portion 242 of the rear wall 24 ofthe container 2. Subsequently, the flux expands since it meets anexpansion defined by the seat 4 immediately at the base, that isupstream of the cooling fan 8 with respect to the direction of the fluxof the air.

The expansion advantageously allows to increase the volume of the airthat is forced against the condenser 7 by the fan 8. The result is thatthe more air hit the condenser and the greater the cooling capacity willbe. Moreover, as the direction of the air flux is basically axial withrespect to the rotation axis of the fan, the same flux is very ordered,that is without turbulences which slow down the flux speed andstagnation. Therefore there are not load losses or, in other words, lossof efficiency. In fact, the less the air remains and is stagnant incontact or in the proximity of the condenser and the more the heat isremoved rapidly.

It has advantageously been devised that the flux regulation, as justdescribed, allows the use of a refrigeration system with betterperformances (COP) with respect to the systems used for the built-indomestic blast chillers of the prior art. In fact, it is possible to useas refrigerant fluid R600a gas. This gas in the blast chiller of theinvention works at lower pressures compared with the traditional gasesused in the previously described blast chillers since it has shown abetter efficiency regarding heat exchange. Consequently, it is possibleto use compressors which work at lower pressures, and that is,compressors that absorb less power while operating. Furthermore, havingto resist lower pressures, they are provided with more cost effectivecomponents as production costs are concerned.

Furthermore, downstream of the condenser 7, that is after the air haspassed through it and thus been heated, the flux meets again a narrowingdefined by the communicating opening O4 between the compartment S1 andthe compartment S3 above. This causes an acceleration of the fluxexiting the opening O4 upwards resulting in an easier removal of the hotair.

In EP1098149, on the contrary, the air downstream of the condenserundergoes a slowing down due to the 90 degree deviation.

Consequently, a further object of the present invention is a process forcooling the “hot” component (condenser and compressor) of a built-indomestic blast chiller, comprising the steps of:

-   -   providing a built-in domestic blast chiller 1 comprising a front        wall 20, two side walls 21, an upper wall 22, 32, a lower wall        23, 31 and a rear wall 24, the latter provided with a first        portion 241 extending from the upper wall 22, 32 towards the        lower wall 23, 31 inclined away from the front wall 20 and a        second portion 242 extending orthogonally to said lower wall 23,        31, said first portion 241 defines a seat 4 to receive a        condenser 7, a compressor 6 and a cooling fan 8, and said second        portion 242 forms, on the contrary, a suction zone of the        cooling air, which zone is positioned substantially axially to        said fan 8;    -   switching on the fan 8 to create an in-flux of cooling air        directed rectilinearly and orthogonally to the surface of major        thermal exchange of the condenser 7, travelling first a zone        upstream of the fan with a flux being substantially axially        aligned with said fan, and then an expansion zone in        correspondence of the condenser 7.

The process preferably comprises the availability of a blast chiller asthe one previously described.

Furthermore, the process can also comprise a further step of narrowingthe air flux after having crossed said condenser in order to acceleratethe removal of the hot air. Preferably, the rear wall of the built-infurniture unit cooperates with the wall 24 to form a suction channelhaving a reduced section followed by an expansion zone, as previouslydescribed.

Further, it is to note that the inner space defined by the rear wall 24and by the other walls of the container 2, or by similar walls of thebox 3, comprises a lower zone 33 (identified by the dashed line inFIG. 1) having a depth such that it allows to receive baking sheets,trays or grills having the typical dimensions of baking sheets oftraditional built-in domestic ovens, that is 460 mm±20 mm width and 360mm±20 mm depth.

In a portion above said lower zone 33, there is, instead, accommodatedthe “cold” component of the heat pump system, that is the evaporator 9together with the corresponding fan 10 (FIG. 1), in a completelytraditional way.

From the foregoing, it is apparent that the drawbacks related to thebuilt-in domestic blast chillers of the prior art have been removed and,at the same time, important advantages have been reached.

In document EP1098149 the vertical portion and the inclined portion areplaced side by side horizontally and not vertically aligned, that is notvertically one on top of the other as in the present invention. In otherwords, by that it is meant that they are vertically one on top of theother, thus forming a vertical flux along the sole rear wall 24.

Furthermore, the vertical portion of the rear wall, extending itselfalmost completely above the fan, does not contribute, in a significantmanner, to create the flux of the cooling air. The air which is in thatzone tends, on the contrary, to stagnate or to create more unwantedturbulences.

In EP 1098149 the air flux sucked horizontally reaches the rear wallwhere it deviates by 90 degrees upwards below the fan.

It is then apparent that the air fluxes in the expansion zone and in theeventually narrowing zone in EP 1098149 are orthogonal, while in thepresent invention they are rectilinear.

Document EP 1098149 hence implies a load loss as it has been describedand criticised in the present description.

In fact, the maximum experimental effort has been devoted in order tooptimize the positioning of the condensing system providing a suctionchannel of the air upstream of the condenser, followed by an expansionzone immediately below the condenser itself. It has experimentally beenseen that this configuration makes it possible an optimal air flux sincethe air reaches the condenser in a very ordered manner, axially alignedwith the cooling fan and therefore without any turbulences which causeload/efficiency losses differently from the prior art that has 90degrees deviations of the air path. Moreover, the combination of thesuction channel and of the expansion zone integrated in the built-infurniture unit allows the air exit at the necessary speed in order toreduce the temperature as much as possible. In practice the geometry ofthe ventilation channel and its section, that have been set after agreat number of numerical analyses and laboratory tests, has made itpossible to find the optimal positioning of the “hot” component in aseat of the blast chiller such that it is possible to accommodate bakingsheets, without compromising the performance of the refrigerationsystem.

In fact, it has been discovered that such geometry allowed to reduce thedimensions of the operating components of the refrigeration systemwithout diminishing its performances. In fact, the fluid R600a used asrefrigerant has a better performance with respect to the thermalexchange and does not need great operating pressures. Consequently, theperformance as regards COP is improved and the power absorbed by thecompressor is reduced. All this advantageously results in loweringproduction costs. It is also to take into consideration that bypositioning the compressor in the vicinity of the condenser, relativelylong connections are not necessary therefore resulting in furtherreduction of components and of structural complexities.

A further advantage derives from the fact that the air suction frontgrilles or louvers are not any more necessary as in the case ofEP1098149, besides not much appreciated by the market, resulting in thesimplification and economy of the entire blast chiller structure.

A further advantage is given by the use of an ecological refrigerantfluid such as R600a type.

A great number of constructive modifications to the blast chiller of thepresent invention may be made by the skilled in the art without, anyway,departing from the scope of the invention as defined in the appendedclaims.

For example, the forms of the blast chiller walls may be modifieddepending on particular requirements or preferences. Anyhow, theessential characteristic of the invention is that of favouring arectilinear and ordered air flux upstream of the fan 8. Therefore, it isa sufficient and necessary condition that from the lower wall 23 of theblast chiller a guide (or open or closed channel) extends that guidesthe air axially aligned with the fan 8, followed by the seat 4 toaccommodate the entire “hot” component. This in order to achieve anoptimal air flux and at the same time to form an inner space for bakingsheets having dimensions the same as those of the traditional built-indomestic ovens.

The materials used to make the container 2 and the box 3 are usually ofmetal and in particular of stainless steel.

Furthermore, the box 3 may comprise an electric resistor (not shown) forcooking at low temperatures or for defrosting.

Advantageously, the blast chilling system may comprise a tray 11 tocollect the mist being positioned in contact to the second portion 242of the rear wall 24 and close to the compressor 6. It is to note that inthis position the tray 11 contributes to partially guide the air fluxbelow the fan 8 of the cooling air, thus concentrating here the greaterpart of the air resulting in less dissipation. Anyway, a part of theflux contacts the tray 11 and the compressor 6 so that to help theevaporation of the mist in the tray from one hand and at the same timeto brush the compressor on the other hand.

A coil (not shown) may also be coupled to the tray 11 to increase thecapacity of evaporation of the mist.

1. Built-in domestic blast chiller comprising a container to reversiblyclose a food treatment box, the container in turn comprising a frontdoor, two side walls, an upper wall, a lower wall and a rear wall,wherein said rear wall comprises a first portion extending form theupper wall towards the lower wall inclined away from the door, and asecond portion extending form said first portion orthogonally to saidlower wall in a way that said first portion is on top of said secondportion, said first portion forming a seat to receive a cooling fan acondenser being positioned just upon the fan, and a compressor, thefirst portion also forming an expansion zone for the cooling air,whereas said second portion forming a guide for suction of the coolingair, which guide is positioned substantially axially to said fan saidguide for suction having a section that is smaller than the section ofsaid seat.
 2. Blast chiller according to claim 1, wherein said seatcomprises a support, provided with apertures, to support the compressor,the condenser and the fan for cooling the compressor and the condenser.3. Blast chiller according to claim 2, wherein the condenser is mountedjust upon the fan in order to fully receive the air blown by the fanitself and the compressor is mounted laterally to the fan and thecondenser in order to be brushed at least in part by the cooling air. 4.Blast chiller according to claim 1, wherein the rotating axis of the fanis orthogonal to the surface of major thermal exchange of the condenserand the fan is at the same time substantially axially aligned with thesuction guide positioned lower to the seat in order to create an airflux substantially rectilinear.
 5. Blast chiller according to claim 1,wherein the internal space defined by the rear wall comprises a lowerzone having a depth adapted to receive backing sheets, trays or grillshaving typical dimension of the corresponding baking sheets of abuilt-in domestic woven.
 6. Blast chiller according to claim 1, whereinthe refrigerant fluid is R600a gas.
 7. Blast chiller according to claim1, comprising a tray to collect the mist, the tray being positioned incontact to the second portion of the wall rear and close to thecompressor so that to contribute to partially guide the air flux belowthe fan, however a part of the flux contacting also the tray and thecompressor so that to help the evaporation of the mist form one hand andat the same time to brush the compressor.
 8. Process for cooling acondenser and a compressor of a built-in domestic blast chiller,comprising the steps of: providing a built-in domestic blast chillercomprising a front door, two side walls, an upper wall, a lower wall anda rear wall, said rear wall being provided with a first portionextending form the upper wall towards the lower wall inclined away fromthe door, and a second portion extending form said first portionorthogonally to said lower wall, said first portion forming a seat toreceive a condenser, a compressor and a cooling fan, and a secondportion forming a suction zone of the cooling air, which zone ispositioned substantially axially to said fan switching on the fan tocreate an in-flux of cooling air directed rectilinearly and orthogonallyto the surface of major thermal exchange of the condenser, travellingfirst a zone upstream of the fan with a flux being substantially axiallyaligned with said fan, and then arriving at an expansion zone, whichzone accommodates the condenser.
 9. Process according to claim 8,further comprising a step of narrowing of the air flux after havingcrossed said condenser in order to accelerate the removal of the hotair.